(a) Field of the Invention
The present invention relates to an automatic correction apparatus for a trajectory of a projectile, and more particularly, to an automatic correction apparatus for a trajectory of a projectile, which can remarkably improve quick action to targets at various distances, and a correction method using the same.
(b) Description of the Related Art
The existing firearms have hitherto employed a target aiming method using a front sight and a rear sight, but this method has shortcomings as follows: it takes long time to line up a sight line, a gun barrel and a target; precision is significantly deteriorated; and a lot of bullets are consumed until hitting the target. To solve these shortcomings, an optical sight based on a dot sight has been developed. Such a dot sight is configured to hit a target point when fired even though a shooters sight line is not aligned with the gun barrel of the firearm as long as a dot reflected on an inner mirror of the sight is aligned with the external target. This dot sight must be more improved than the conventional method in which the front sight and the rear sight are used and the target can be hit by firing only when the shooter's sight fine is aligned with the gun barrel of the firearm. That is, the optical sight based on the dot sight can largely reduce time taken in lining up the shooter's sight line, the gun barrel of the firearm, and a target point, thereby showing its ability even in a situation required to be quickly coped with.
As shown in FIG. 1, such a conventional optical sight based on a dot sight includes an inner body tube alignment adjuster 7 on a top of a sighting housing 2, a lower fixing grill 26 detachably connected in the form of rail to an upper end of a rear sight package of a rifle, a protective window 10 in a front end of the housing 2, a light emitting diode (LED) 8 serving as a light source at a predetermined position of the upper end of the inner tube body of the housing 2, and a reflective mirror 9 having a certain curvature and placed behind the protective window 10 within the housing 2.
In general, the reflective mirror 9 is coated so that an observer's (i.e., a user's) eyes can view a front end of the optical sight 1 based on the dot sight and an LED light point of a light beam having a wavelength of about 650 nm can be reflected. The reflective mirror 9 allows the observer's (i.e., the user's) eyes to view the front end of a dot sight device 1 and reflects the light point of the LED 8 emitting the light beam having a wavelength of about 650 nm toward a rear end. The observer (i.e., the user) fires when the light point of the LED is matched with the target, and it is thus easy to aim at the target. In theory, a spot light source made by the LED 8 placed within the optical sight 1 based on the dot sight is intended to be reflected from the reflective mirror 9 and incident in parallel with the observer's eyes, and this parallelization is intended to be aligned with a bullet firing axis of the firearm. However, if the parallelization of the optical sight 1 based on the dot sight is not aligned with the bullet firing axis of the firearm, the target point cannot be hit even though the observer lines up a beam dot of the LED 8 with the target point. Therefore, in order to line up the parallelization of the optical sight 1 based on the dot sight with the bullet firing axis of the firearm, the inner tube body adjuster 7 having vertical and horizontal functions is provided to thereby align an optical axis of the inner tube body with the bullet firing axis of the gun barrel.
Meanwhile, if the target point is varied in distance, such an optical sight based on the dot sight sometimes fails in hitting the target point even though the dot of the dot sight is aligned with the target point. Accordingly, a patent (Korean Patent No. 10-0906159) for an optical sight using a dot sight has been granted and provided, in which a distance-based rear sight or a means having a similar function with the means for manually adjusting the height of the front sight like the method using the front sight and the rear sight is applied to the optical sight using the dot sight, so that the optical axis of the dot sight, the parallelization of the gun barrel axis, and horizontal correction can be manually adjusted in accordance with distance to thereby correct a trajectory.
However, if a plurality of targets approaches from various distances or moves, the optical sight using the dot sight with a manual trajectory correction means may be deteriorated in speed of carrying out manual corrections one by one. That is, to take change in an impact point according to distance into account, parallelization between an optical axis of a dot sight main body and a firing axis of the gun barrel was mechanically adjusted and used. However, the mechanical adjustment causes a deadly problem that distance change cannot be quickly coped with, and therefore a target may be missed or an effective hit according to situations is impossible.